燃煤烟气体积热值比的提出及应用

Putting-forward and Applications of the Volume and Heating Value Ratio of Flue Gases Produced in Combustion of Coal

火电厂炉后环保系统设计中,烟气量是一项重要参数,正常设计中无法判断设计取用烟气量的大小。本论文通过燃煤分析,提出燃煤烟气体积热值比,即每千克燃煤产生的烟气量与收到基低位发热量的比值。湿基燃煤烟气体积热值比按照无烟煤、贫煤、烟煤、褐煤的顺序呈现逐渐变大的趋势,影响不同煤种烟气体积差别的主要因素为燃煤中收到基全水分。干基燃煤烟气体积热值比与燃煤成份关系不大,在较小范围内变化。在设计过程中,通过计算燃煤烟气体积热值比可以判断本工程设计采用的烟气量是偏小还是偏大,从而指导后续设备选型中烟气量裕量选择。

Recently,the ultra low emissions are required in thermal power plants in China,the performance of flue gas environmental protection equipment items at the tail portion of existing boilers are requested to be improved continuously and an even higher standard for design of environmental protection equipment items is proposed. As an important parameter,the flue gas flow speed seems more and more important. Through an analysis of coal burned,a ratio between the flue gas volume and the heating value of coal burned was proposed,i. e. a ratio between the flue gas volume produced by each kilogram of coal burned and the as-received basis low heating value. Through this ratio,one can know clearly the flue gas volume produced by various coal ranks. In the design process,through calculating the volume and heating value ratio of coal burned,one can make a judgement whether the flue gas volume adopted in the design of a project is excessively small or large,therefore offering guidance for subsequently choosing the allowance of the flue gas volume in type selection of equipment items.